org.apache.commons.jrcs.diff

Class Delta

java.lang.Object

org.apache.commons.jrcs.util.ToString

org.apache.commons.jrcs.diff.Delta

Direct Known Subclasses:

AddDelta, ChangeDelta, DeleteDelta

public abstract class Delta
extends ToString

Holds a "delta" difference between to revisions of a text.

Version:

$Revision$ $Date: 2006-04-12 18:30:19 +0100 (Wed, 12 Apr 2006) $

Author:

Juanco Anez, Brian McBride

See Also:

Diff, Chunk, modifications 27 Apr 2003 bwm Added getOriginal() and getRevised() accessor methods Added visitor pattern accept() method

Field Summary

Fields

Modifier and Type	Field and Description
protected Chunk	original
protected Chunk	revised

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Delta() Creates an uninitialized delta.
protected	Delta(Chunk orig, Chunk rev) Creates a delta object with the given chunks from the original and revised texts.

Method Summary

Modifier and Type	Method and Description
abstract void	accept(RevisionVisitor visitor) Accepts a visitor.
abstract void	applyTo(List target) Applies this delta as a patch to the given text.
Chunk	getOriginal() Accessor method to return the chunk representing the original sequence of items
Chunk	getRevised() Accessor method to return the chunk representing the updated sequence of items.
protected void	init(Chunk orig, Chunk rev) Initializaes the delta with the given chunks from the original and revised texts.
static Delta	newDelta(Chunk orig, Chunk rev) Returns a Delta that corresponds to the given chunks in the original and revised text respectively.
void	patch(List target) Applies this delta as a patch to the given text.
String	toRCSString(String EOL) Converts this delta into its RCS style string representation.
abstract void	toRCSString(StringBuffer s, String EOL) Converts this delta into its RCS style string representation.
void	toString(StringBuffer s) Converts this delta into its Unix diff style string representation.
abstract void	verify(List target) Verifies that this delta can be used to patch the given text.

Methods inherited from class org.apache.commons.jrcs.util.ToString

arrayToString, arrayToString, stringToArray, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

original

protected Chunk original

revised

protected Chunk revised

Constructor Detail

Delta

protected Delta()

Creates an uninitialized delta.

Delta

protected Delta(Chunk orig,
                Chunk rev)

Creates a delta object with the given chunks from the original and revised texts.

Method Detail

newDelta

public static Delta newDelta(Chunk orig,
                             Chunk rev)

Returns a Delta that corresponds to the given chunks in the original and revised text respectively.

Parameters:

orig - the chunk in the original text.

rev - the chunk in the revised text.

init

protected void init(Chunk orig,
                    Chunk rev)

Initializaes the delta with the given chunks from the original and revised texts.

verify

public abstract void verify(List target)
                     throws PatchFailedException

Verifies that this delta can be used to patch the given text.

Parameters:

target - the text to patch.

Throws:

PatchFailedException - if the patch cannot be applied.

patch

public final void patch(List target)
                 throws PatchFailedException

Applies this delta as a patch to the given text.

Parameters:

target - the text to patch.

Throws:

PatchFailedException - if the patch cannot be applied.

applyTo

public abstract void applyTo(List target)

Applies this delta as a patch to the given text.

Parameters:

target - the text to patch.

Throws:

PatchFailedException - if the patch cannot be applied.

toString

public void toString(StringBuffer s)

Converts this delta into its Unix diff style string representation.

Overrides:

toString in class ToString

Parameters:

s - a StringBuffer to which the string representation will be appended.

toRCSString

public abstract void toRCSString(StringBuffer s,
                                 String EOL)

Converts this delta into its RCS style string representation.

Parameters:

s - a StringBuffer to which the string representation will be appended.

EOL - the string to use as line separator.

toRCSString

public String toRCSString(String EOL)

Converts this delta into its RCS style string representation.

Parameters:

EOL - the string to use as line separator.

getOriginal

public Chunk getOriginal()

Accessor method to return the chunk representing the original sequence of items

Returns:

the original sequence

getRevised

public Chunk getRevised()

Accessor method to return the chunk representing the updated sequence of items.

Returns:

the updated sequence

accept

public abstract void accept(RevisionVisitor visitor)

Accepts a visitor.

See the Visitor pattern in "Design Patterns" by the GOF4.

Parameters:

visitor - The visitor.